Download GE - ECM Motor Technology and Troubleshooting

GE - ECM Motor Technology
and Troubleshooting
Presented by The RLCS Engineering
Product Field Support
Airflow
• If SPEED is constant, CFM changes with
Static Pressure
• To hold CFM constant, SPEED must
change with Static Pressure
Unregulated Versus Regulated Airflow
No System Balancing Required!
Set the airflow level
and go!
0.8
0.7
PRESSURE
0.6
System airflow is starved
0.5
0.4
0.3
0.2
0.1
0
1300
1400
1500
1600
1700
1800
Airflow (CFM)
1900
2000
2100
2200
2300
2400
Overblowing the system
• poor moisture removal
• high power consumption
The ECM’s Benefits in HVAC
ECM
Airflow Control
• Constant airflow over wide external pressure changes
• Greater customer comfort and satisfaction
PSC
• External pressure change causes:
• airflow variation as filter loads
• reduced performance
• poor latent/sensible capacity control
Air Volume vs Ext SP
Cu Ft/min
1-ph PSC Lo
1-ph PSC Med
1-ph PSC HI
1700
1600
1500
1400
1300
1200
1100
1000
900
0.0
0.2
0.4
0.6
0.8
Ext Static Pressure (" H2O)
1.0
ECM
What's an ECM ?
The highest efficiency motor there is! … A DC Motor
• Without mechanical Brushes and Commutator
• Permanent Magnet Rotor
• Rotor losses are nearly zero
• Stator is driven from an Inverter which,
in turn, is powered from the AC line
• The “Electronic Inverter”
• “Commutates” the stator magnetic fields
• Synchronous machine
• Speed and torque controlled
• Interfaces to the HVAC controls
ECM Issues - Furnaces / Fan
coils
• Prior to potted controls:
– Moisture was responsible for most failures
• The Power Transistors were the most common
failure
• Contaminants from the air, added to the
moisture/condensation, were also a concern
• Now, most common failure:
– NO defects found
ECM 2.3 - Potted Control
• Produced in fan coils
and Tyler products
since October 1998
• Produced in furnaces
since September 1999
Types of ECM Control
• Thermostatically Controlled
– Fan Coils / Non-condensing furnaces /
Packaged Units
• Pulse Width Modulation (PWM)
– Split systems (A/C & Heat Pump)
– Condensing Furnaces
Thermostatically Control
• ECM logic for fan coils, non-condensing
furnaces and Tyler products
– Uses Full, Half, Positive, Negative or No Sine
wave
– Bases CFM on predetermined CFM curves
• Models programmed differently
– CFM is controlled by adjusting torque in response
to RPM
– RPM is sensed by the motor’s “back EMF”
– Always uses the “highest CFM” of what is being
called for
FAN COIL EASY SELECT BOARD
DH - Dehumidification
R - 24 VAC
W1 - 1st stage Elect Ht
W2 - 2nd stage Elect Ht
Y1 - 1st stage Compressor
YY/2 - 2nd stage Compressor
or single stage Compressor
G - Fan
O - Reversing Valve in Clg
C - Common
Hum - Humidifier (24VAC)
AUX - Auxiliary (24VAC)
EAC
ECM Logic
Pulse Width
Modulation
PWM
Pulse Width Modulation
(PWM)
• PWM is a simple way of commanding
airflow (CFM), as defined from an external
device (2 wire method)
• The variable speed circuit board supplies
this signal to the motors
90% ECM MOTOR
TECHNOLOGY “PWM”
Pulse Width
Modulation (PWM)
Equation determines
the slope of the curve
Based on duty cycle
CFM 2
CFM 1
Min
PWM
Max
PWM
Duty Cycle
Voltage (dc)
The amount of “ON-TIME” per cycle
PWM= A/B or PWM%= A/B% (a=b=full speed,
emergency heat, sw 4 - on)
A
B
Time
ECM logic for variable speed
condensing gas furnaces
• Furnace control board sends a PWM signal
to the motor
• Control logic is contained in the Furnace
control board
– Airflow is determined by the model or
“personality plug” on furnace board
• PWM can be read by an oscilloscope
– will be seen as a square waveform
38TDA/YDA, 598W
Condensing Units
• Uses logic in Circuit Board of outdoor unit
– Control Board sends a PWM signal to the
motor
– Signal can be read with a “DC” volt meter, with
motor at full speed (22º<OAT>90º) at PW1,
PW2
• 16-20 VDC with motor connected
• 20-40 VDC with motor Disconnected
Control Board Setups
FAN COIL EASY SELECT BOARD
DH - Dehumidification
R - 24 VAC
W1 - 1st stage Elect Ht
W2 - 2nd stage Elect Ht
Y1 - 1st stage Compressor
YY/2 - 2nd stage Compressor
or single stage Compressor
G - Fan
O - Reversing Valve in Clg
C - Common
Hum - Humidifier (24VAC)
AUX - Auxiliary (24VAC)
EAC
FK4C Fan Coil
• Size 002
• 3 ton Heat Pump
• 15 KW electric Heat
•
Setup
Easy Select Board
Easy Select Board
HP-COMFORT
LO CFM
ENH DELAY
Easy Select Board
• Remove J1 jumper to
activate dehumidify
mode
• Remove J2 jumper to
separate W1 & W2
(Intelligent Heat
staging)
ECM setup for Variable Speed
Condensing Gas Furnace
2 Sets of three (3) field selectable dip switch banks,
Model Plug, and Thermostat inputs determine airflow.
Status & Diagnosis LED’s
Continuous Fan (CF)
A/C Setup
Furnace Test, Blower, & Delay
Model Plug
MVP furnace Board Setup
(changes made in idle mode)
80% Variable Speed Control
Board
Tyler Packaged Units
ECM Troubleshooting
ECM Troubleshooting
• All troubleshooting information can be
found in Service Manuals
• Fan Coil (catalog# 03FA-5A0)
• Mid-efficiency furnace (catalog# 535-800)
• Infinity furnace (catalog# 565-829)
• ECM Troubleshooting Guide / Tyler
products (catalog# 534-897)
All ECM Motors
• Slight “cogging” or rocking is inherent to all ECM
motors
– motor is finding its location between stator and rotor and is
determining rotation
• “Rumbling” sound during startup and shutdown
– System mechanical resonance (approx 300-400rpm), three
(3) permanent magnets (stators) cause the rotor to have a
“rumble” during low RPM’s
• “Fixes”
– Don’t replace motor!
– Isolate sound: Canvas duct connectors, rubber grommets,
etc.
Power Plugs
High Voltage
5 PIN CONNECTOR
Low Voltage
16 PIN CONNECTOR
ECM Warning !!!
NEVER remove or connect the 5 PIN HIGH
VOLTAGE CONNECTOR of the motor, with
the power ON !!
- High Voltage is always present at the motor
- Arcing could damage electronics.
ECM warning!!!
• ECM motors should NOT be tested
UNLESS under LOAD
– Erratic motor behavior could occur without
a load (static pressure)
High Voltage Power Connector
Troubleshooting ECM Motors
Check HIGH VOLTAGE at motor
Pins 4, 5 of five pin connector
SHOULD ALWAYS HAVE HIGH VOLTAGE
120 Volts for furnaces
240 Volts for fan coils / Tyler products
Low Voltage Connector
Troubleshooting ECM Motors
Check LOW VOLTAGE at the motor
Pins 1(C), 12(R) of sixteen pin connector
SHOULD ALWAYS HAVE ~24VAC VOLTAGE AT THE
MOTOR
If not, check for voltage at circuit board
ECM Motor shaft turns,
but not smoothly
If the shaft (with blower wheel disconnected) is
difficult to turn with the motor control attached:
- and turns freely with the control disconnected,
then the control is damaged.
- and does not turn free with the control
disconnected, then the motor is damaged. Verify
continuity of windings (motor leads to unpainted
motor end plate). They should be >100KW.
ECM Motor won’t stop
running
• Check for good ground between
–
–
–
–
motor ground
transformer common lead
Thermostat wiring
Control Board
• Remove 12 pin connector, if motor stops it’s control
wiring.
• If it continues to run, motor is bad.
Replacement Issues
• Insert Blower motor as far into cradle as possible
– air over motor helps keep motor cool
• Verify proper installation of motor to prevent
water entering pin connections
– Drip legs, proper positioning
• Beware of electronic thermostats (90% furnaces)
– units that notch the waveforms
– “Power-Stealing”
Notes on Mounting and Orientation
A Few Factors Are Critical When mounting Motor/Control
• Condensate or droplets can accumulate in harness
• Orient connectors "down" whenever possible
• "Drip Loops" are important!
Motor Mounting to Blower Can Control Noise
• Loose blower wheel on shaft can affect starting and will be noisy
• Loose motor in mount or loose attachment to housing will cause noise
and poor starting
RCD - Fan Coil Replacement
Modules
RCD - Furnace Replacements
Module
Pulse Width Modulation (PWM)
Troubleshooting
Infinity Troubleshooting Guide
• Example: Inducer Motor
– Use Troubleshooting Guide
– Check voltages
• Line, PW and Feedback voltages
Infinity Inducer Motor
• Power / high voltage
– pins 6 & 12
• PW voltage
– pins 2 & 10
• Feedback voltage
– pins 2 & 1
– pin 4 /ground
Advanced Product Monitor
(APM)
• APM kit will help troubleshoot the furnace,
including the ECM motors
• Requires:
– Laptop
– Software
– B&B RS485 Adapter
ECM Motor Simulator
(for HK42FZ003 /012 Only)
1. Shut off power to the unit
2. Disconnect PL13 and plug it into the ECM
Motor Simulator
3. Turn power on to unit
4. Put setup switch SW-6 to the “ON” position
5. Observe fault code displayed
Thermostatic ECM
Troubleshooting
Troubleshooting ECM Motors
Call for W1, check LOW VOLTAGE
pins 1, 2 of sixteen pin connector
Call for W2, check pins 1, 13
(SHOULD HAVE ~24VAC)
Troubleshooting ECM Motors for
Fan Coils
Check LOW
VOLTAGE at R and C,
at the control board
Pins 8, 9 of twelve pin
connector
(SHOULD HAVE
~24VAC)
FAN COIL PINS @ CIRCUIT BOARD
CHECK W1, Y/Y2, Y1 (USES 24VAC)
AUX/HEAT KW/CFM, AC/HP SIZE, SYSTEM TYPE, AC/HP ADJUST, ON/OFF
DELAY, CONTINUOUS FAN (Uses Half Wave Signals)
Operating Mode
Electric Heating
1-Speed A/C, Cooling
2-Speed A/C, Low Cooling
2-Speed A/C, High Cooling
1-Speed HP, Cooling
2-Speed HP, Low Cooling
2-Speed HP, High Cooling
1-Speed HP, Heating
2-Speed HP, Low Heating
2-Speed HP, High Heating
1-Speed HP, Heating
2-Speed HP, Low Heating
2-Speed HP, High Heating
Continuous Fan- Lo
Continuous Fan- Med
Continuous Fan- Hi
Thermostat Input
having 24VAC W1, Pin 7 C, Pin 9
R,W1,W2
24VAC
0
R,Y/Y2,G
0
0
R,Y1,G
0
0
R,Y1,Y/Y2,G
0
0
R,Y/Y2,G,O
0
0
R,Y1,G,O
0
0
R,Y1,Y/Y2,G,O
0
0
R,Y/Y2,G
0
0
R,Y1,G
0
0
R,Y1,Y/Y2,G
0
0
R,Y/Y2,G, W1
24VAC
0
R,Y1,G, W1
24VAC
0
R,Y1,Y/Y2,G, W1 24VAC
0
R,G
0
0
R,G
0
0
R,G
0
0
R, Pin 8 Y/Y2, Pin 2 Y1, Pin 3
24VAC
0
0
24VAC
-12VDC
0
24VAC
0
-12VDC
24VAC
-12VDC
-12VDC
24VAC
-12VDC
0
24VAC
0
-12VDC
24VAC
-12VDC
-12VDC
24VAC
-12VDC
0
24VAC
0
-12VDC
24VAC
-12VDC
-12VDC
24VAC
-12VDC
0
24VAC
0
-12VDC
24VAC
-12VDC
-12VDC
24VAC
0
0
24VAC
0 -12VDC'
24VAC -12VDC''''
0
Newest FK4C installation
instructions
• New instructions have more troubleshooting
tables and examples
• Form # IM-FK4C-07
• Catalog# 63FK-4C3
Jumper
Wire
Pin 9
Pin 2
-12vdc
-12vdc
Jumper
Wire
Pin 4
Pin 2
24vac
24vac
Other Contributing Factors
• Fan coils are a
“DrawThru” design
• If not properly trapped,
the water will hold in
drain pan
• Water could drip on motor
in downflow application
• Make trap IS DONE
CORRECTLY!!
Troubleshooting ECM Motors for
80% two speed furnaces
Check LOW VOLTAGE at R-C terminals, at the control board
Pins 14, 9 of fourteen pin connector
SHOULD ALWAYS HAVE ~24VAC
80% 2 SPEED FURNACE PINS AT
EASY SELECT CIRCUIT BOARD
Check W1, W2, Y/Y2, Y1 (Uses 24VAC)
AUX/HEAT KW/CFM, AC/HP SIZE, SYSTEM TYPE, AC/HP ADJUST, ON/OFF
DELAY, CONTINUOUS FAN (Uses Half Wave Signals)
Operating Mode
1-Speed A/C, Cooling
2-Speed A/C, Low Cooling
2-Speed A/C, High Cooling
1-Speed HP, Cooling
2-Speed HP, Low Cooling
2-Speed HP, High Cooling
1-Speed HP, Heating
2-Speed HP, Low Heating
2-Speed HP, High Heating
Low Fire, Heating
High Fire, Heating
Thermostat
Input having
W,W1,
24VAC
Pin PL7-6
R,Y/Y2,G
0
R,Y1,G
0
R,Y1,Y/Y2,G
0
R,Y/Y2,G,O
0
R,Y1,G,O
0
R,Y1,Y/Y2,G,O
0
R,Y/Y2,G
0
R,Y1,G
0
R,Y1,Y/Y2,G
0
R,G, W1
24VAC
R,G, W1, W2
24VAC
W2, Pin
PL4-4
0
0
0
0
0
0
0
0
0
0
24VAC
C, Pin C, Pin
PL7-9 PL7-8
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
R, Pin
PL7-14
24VAC
24VAC
24VAC
24VAC
24VAC
24VAC
24VAC
24VAC
24VAC
24VAC
24VAC
Y/Y2, Pin
PL7-1
-12VDC
0
-12VDC
-12VDC
0
-12VDC
-12VDC
0
-12VDC
0
0
(WITH 16 PIN MOTOR CONNECTOR DISCONNECTED)
Y1, Pin
PL7-3
0
-12VDC
-12VDC
0
-12VDC
-12VDC
0
-12VDC
-12VDC
-12VDC
0
Troubleshooting ECM Motors for
Tyler Products
CHECK LOW
VOLTAGE R-C AT THE
CONTROL BOARD
PINS PL2-5, PL2-3 OF 7
PIN CONNECTOR
SHOULD ALWAYS
HAVE ~24VAC
TYLER PRODUCT PINS
AT CIRCUIT BOARD
CHECK W1, G, Y/Y2, Y1 (USES 24VAC)
AUX/HEAT KW/CFM, AC/HP SIZE, SYSTEM TYPE, AC/HP ADJUST, ON/OFF
DELAY, CONTINUOUS FAN (Uses Half Wave Signals)
Unit & Operating Mode
Electric & Heating
1-Speed A/C Cooling
2-Speed A/C Low Cooling
2-Speed A/C High Cooling
1-Speed HP Cooling
1-Speed HP Heating
2-Speed HP Low Cooling
2-Speed HP Low Heating
2-Speed HP High Cooling
2-Speed HP High Heating
Continous Fan
Thermostat Input W, Pin G, Pin
C, Pin
having 24VAC
PL2-1
PL2-2
PL2-3
R,W2,W3,E
24VAC 24VAC
0
R,Y/Y2,G
0
24VAC
0
R,Y1,G
0
24VAC
0
R,Y/Y2,G
0
24VAC
0
R,Y/Y2,G,O
0
24VAC
0
R,Y/Y2,G
0
24VAC
0
R,Y1,G,O
0
24VAC
0
R,Y1,G
0
24VAC
0
R,Y/Y2,Y1,G,O
0
24VAC
0
R,Y/Y2,Y1,G
0
24VAC
0
R,G
0
24VAC
0
C, Pin
PL2-4
0
0
0
0
0
0
0
0
0
0
0
R, Pin
Y/Y2, Pin Y1, Pin
PL2-5
PL2-6
PL2-7
24VAC
0
0
24VAC 24VAC
0
24VAC
0
24VAC
24VAC 24VAC
0
24VAC 24VAC
0
24VAC 24VAC
0
24VAC
0
24VAC
24VAC
0
24VAC
24VAC 24VAC 24VAC
24VAC 24VAC 24VAC
24VAC
0
0
(WITH 16 PIN MOTOR CONNECTOR DISCONNECTED)
Proper Ductwork Installation
• Check existing ductwork static pressure
• Determine existing equipment CFM
• Use Product Data Sheet to determine that
new equipment will work with existing
ductwork or if it will require ductwork
modifications
– See following examples
Condensing Furnace
Fan Performance
• ECM Motor’s RPM
range is 250-1300rpm
• Outside of this range,
a Status Code 44 will
occur
– High fire will default
to 1200rpm
– cooling- last valid
PWM
Fan Coil Fan Performance
• Performance capable
of 0.9” w.c. in some
applications
– Torque”cad-back” will
limit RPM
– Oscillation can occur
during high static
• Nominal 350cfm/ton
• Airflow can be
adjusted + 15%
or -10%
Additional Fan Coil
Consideration
• Return and Supply
static must be in
“white area” to
prevent condensate
removal from drain
pan
Other things to consider
• An ECM motor will out-perform a PSC
motor in high static situations
– Condensing furnace will display a fault code
(above 1300rpm’s) but still provide more CFM
than standard PSC motor at comparable
external static pressure
– Thermostatically Controlled motors will
provide desired CFM in high static situations